Also, first distinguish between the year number and the temple number posthumous title, and the temple number posthumous title was given after death. ....
We are talking about Emperor Gaozu and Emperor Taizong, both temple names. Generally, the names of temples end with ancestors and sects.
Then there are posthumous title, Emperor Wu of the Han Dynasty and Emperor Jinhui, and this is posthumous title.
The year number was established when the emperor was in office to record the year, that is, how many years of XX.
In the history of China, most emperors in Ming and Qing dynasties only had one title, so later generations took the title as the code name of the emperor. Before Ming and Qing dynasties, the title of emperor code was not used.